This application seeks to renew funding for the ITC Four Country Survey for five additional years. The objective of the ITC Four Country Survey is to evaluate the psychosocial and behavioural effects of national-level tobacco control policies and to understand the commonality and differences of policy effects in four countries - United States, Canada, United Kingdom and Australia. In a prospective cohort design, the participants are 1,500 adult smokers in each country who respond to a 45-minute telephone survey every year for five additional years. The ITC Four Country Survey is the core survey of the global ITC Project, which is conducting parallel cohort surveys of representative samples of adult smokers in 17 countries, inhabited by over half of the world's smokers. The ITC Project is the only international comparative cohort survey of tobacco users, and its focus on evaluating the impact of policies of the Framework Convention on Tobacco Control (FCTC), the first- ever global health treaty, has placed the ITC Project at a unique and central position in providing the evidence base for the FCTC, which in turn has provided guidance to many countries regarding the implementation of strong evidence-based policies. The ITC survey includes measures of smoking behaviour, psychosocial predictors of smoking and quitting, and policy-relevant measures in five major policy domains (1) enhancement of warning labels, (2) elimination or restriction of the terms light or mild cigarette brand descriptors, (3) elimination or restrictions on advertising and promotion of tobacco products, (4) changes in price and taxation, and (5) smoke-free laws. The quasi-experimental design includes both between-country controls and within- country controls, thus allowing rigorous tests of national-level policies. There are 8 specific aims, which will be addressed by ITC Project: (1) examine whether a policy introduced in one country will affect self-reported smoking behaviour, in comparison to other countries where that policy is not changing, (2) examine whether a policy introduced in one country will enhance policy-relevant psychosocial variables in comparison to other countries where that policy is not changing, (3) examine whether a policy introduced in one country will lead to favourable changes in psychosocial variables known to be related to smoking and quitting behaviour, in comparison to other countries where that policy is not changing, (4) examine whether the effects of tobacco control policies may be offset by compensatory behaviours (e.g., price increases leading to shifts toward discount brands rather than to quitting, (5) examine whether the effects of tobacco control policies are moderated by situational and individual-difference factors, (6) identify the psychosocial mechanisms that may explain how tobacco control policies achieve (or fail to achieve) their goals, (7) identify similarities and differences in the factors that relate to smoking and cessation, and (8) evaluate the impact of the potentially forthcoming FDA regulation of tobacco in the U.S. This project has considerable time urgency as the FCTC has progressed into the implementation phase and FDA regulatory changes may occur soon. PUBLIC HEALTH RELEVANCE: This project evaluates the relative effectiveness of national level public health policies related to tobacco control across four countries. National policies have the ability to effectively improve public health by encouraging healthy behaviors or discouraging unhealthy behaviors. Comparisons made between countries with different policy environments, or within countries over time, will illustrate the effectiveness of specific policies in reducing tobacco consumption, providing public health officials with evidence to make informed decisions.